//package com.base;
//
//import org.apache.commons.collections.FastArrayList;
//
//import java.util.ArrayList;
//import java.util.HashMap;
//import java.util.concurrent.*;
//import java.util.concurrent.locks.Condition;
//import java.util.concurrent.locks.LockSupport;
//import java.util.concurrent.locks.ReentrantLock;
//
///**
// * @author: sun.hongliang
// * @create: 2020/06/23 15:39
// */
//public class Main {
//    public static void main(String[] args) throws Exception {
//        ThreadLocal<LRU> threadLocal = new ThreadLocal<>();
//        threadLocal.set(null);
//        threadLocal.get();
//        HashMap<String, Object> map = new HashMap<>();
//        map.put("a", "b");
//        map.remove("a");
//        map.size();
//        ExecutorService executorService = Executors.newFixedThreadPool(10);
//        executorService.execute(null);
//        ConcurrentHashMap<String, String> concurrentHashMap = new ConcurrentHashMap<>();
//        concurrentHashMap.put("a", "b");
//        concurrentHashMap.get("a");
//        CountDownLatch countDownLatch = new CountDownLatch(5);
//        countDownLatch.countDown();
//        countDownLatch.await();
//        Semaphore semaphore = new Semaphore(5);
//        semaphore.acquire();
//        semaphore.release();
//        CyclicBarrier cyclicBarrier = new CyclicBarrier(5);
//        cyclicBarrier.await();
//        LockSupport.park(null);
//
//        ReentrantLock lock = new ReentrantLock();
//        Condition condition = lock.newCondition();
//        lock.lock();
//        try {
//            condition.await();
//        } finally {
//            lock.unlock();
//        }
//        ArrayList list = new ArrayList();
//        list.add(null);
//        FastArrayList fastArrayList = new FastArrayList();
//        fastArrayList.get(1);
//        FastThreadLocal fastThreadLocal = new FastThreadLocal();
//        fastThreadLocal.set(null);
//        fastThreadLocal.get();
//        fastThreadLocal.remove();
//    }
//}
